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From: preeti@linux.vnet.ibm.com (Preeti U Murthy)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC PATCH v3 3/6] sched: pack small tasks
Date: Wed, 27 Mar 2013 10:03:15 +0530	[thread overview]
Message-ID: <5152768B.3020306@linux.vnet.ibm.com> (raw)
In-Reply-To: <1364301443.5053.9.camel@laptop>

Hi Peter,

On 03/26/2013 06:07 PM, Peter Zijlstra wrote:
> On Fri, 2013-03-22 at 13:25 +0100, Vincent Guittot wrote:
>> +static bool is_light_task(struct task_struct *p)
>> +{
>> +       /* A light task runs less than 20% in average */
>> +       return ((p->se.avg.runnable_avg_sum  * 5) <
>> +                       (p->se.avg.runnable_avg_period));
>> +}
> 
> OK, so we have a 'problem' here, we initialize runnable_avg_* to 0, but
> we want to 'assume' a fresh task is fully 'loaded'. IIRC Alex ran into
> this as well.
> 
> PJT, do you have any sane solution for this, I forgot what the result
> of the last discussion was -- was there any?

The conclusion after last discussion between PJT and Alex was that the
load contribution of a fresh task be set to "full" during "__sched_fork()".

task->se.avg.load_avg_contrib = task->se.load.weight during
__sched_fork() is reflected in the latest power aware scheduler patchset
by Alex.

Thanks

Regards
Preeti U Murthy
> 

WARNING: multiple messages have this Message-ID (diff)
From: Preeti U Murthy <preeti@linux.vnet.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Vincent Guittot <vincent.guittot@linaro.org>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linaro-kernel@lists.linaro.org, mingo@kernel.org,
	linux@arm.linux.org.uk, pjt@google.com, santosh.shilimkar@ti.com,
	morten.rasmussen@arm.com, chander.kashyap@linaro.org,
	cmetcalf@tilera.com, tony.luck@intel.com, alex.shi@intel.com,
	paulmck@linux.vnet.ibm.com, tglx@linutronix.de,
	len.brown@intel.com, arjan@linux.intel.com,
	amit.kucheria@linaro.org, corbet@lwn.net
Subject: Re: [RFC PATCH v3 3/6] sched: pack small tasks
Date: Wed, 27 Mar 2013 10:03:15 +0530	[thread overview]
Message-ID: <5152768B.3020306@linux.vnet.ibm.com> (raw)
In-Reply-To: <1364301443.5053.9.camel@laptop>

Hi Peter,

On 03/26/2013 06:07 PM, Peter Zijlstra wrote:
> On Fri, 2013-03-22 at 13:25 +0100, Vincent Guittot wrote:
>> +static bool is_light_task(struct task_struct *p)
>> +{
>> +       /* A light task runs less than 20% in average */
>> +       return ((p->se.avg.runnable_avg_sum  * 5) <
>> +                       (p->se.avg.runnable_avg_period));
>> +}
> 
> OK, so we have a 'problem' here, we initialize runnable_avg_* to 0, but
> we want to 'assume' a fresh task is fully 'loaded'. IIRC Alex ran into
> this as well.
> 
> PJT, do you have any sane solution for this, I forgot what the result
> of the last discussion was -- was there any?

The conclusion after last discussion between PJT and Alex was that the
load contribution of a fresh task be set to "full" during "__sched_fork()".

task->se.avg.load_avg_contrib = task->se.load.weight during
__sched_fork() is reflected in the latest power aware scheduler patchset
by Alex.

Thanks

Regards
Preeti U Murthy
> 


  parent reply	other threads:[~2013-03-27  4:33 UTC|newest]

Thread overview: 103+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-22 12:25 [RFC PATCH v3 0/6] sched: packing small tasks Vincent Guittot
2013-03-22 12:25 ` Vincent Guittot
2013-03-22 12:25 ` [RFC PATCH v3 1/6] Revert "sched: Introduce temporary FAIR_GROUP_SCHED dependency for load-tracking" Vincent Guittot
2013-03-22 12:25   ` Vincent Guittot
2013-03-22 12:25 ` [RFC PATCH v3 2/6] sched: add a new SD_SHARE_POWERDOMAIN flag for sched_domain Vincent Guittot
2013-03-22 12:25   ` Vincent Guittot
2013-03-22 12:25 ` [RFC PATCH v3 3/6] sched: pack small tasks Vincent Guittot
2013-03-22 12:25   ` Vincent Guittot
2013-03-26 12:26   ` Peter Zijlstra
2013-03-26 12:26     ` Peter Zijlstra
2013-03-27 10:21     ` Preeti U Murthy
2013-03-27 10:21       ` Preeti U Murthy
2013-03-27 11:00       ` Vincent Guittot
2013-03-27 11:00         ` Vincent Guittot
2013-04-26 10:30         ` Peter Zijlstra
2013-04-26 10:30           ` Peter Zijlstra
2013-04-26 11:34           ` Vincent Guittot
2013-04-26 11:34             ` Vincent Guittot
2013-04-26 10:18       ` Peter Zijlstra
2013-04-26 10:18         ` Peter Zijlstra
2013-04-26 10:32         ` Preeti U Murthy
2013-04-26 10:32           ` Preeti U Murthy
2013-03-26 12:37   ` Peter Zijlstra
2013-03-26 12:37     ` Peter Zijlstra
2013-03-26 13:00     ` Vincent Guittot
2013-03-26 13:00       ` Vincent Guittot
2013-03-27  4:33     ` Preeti U Murthy [this message]
2013-03-27  4:33       ` Preeti U Murthy
2013-03-27  4:48       ` Alex Shi
2013-03-27  4:48         ` Alex Shi
2013-03-27  8:51         ` Peter Zijlstra
2013-03-27  8:51           ` Peter Zijlstra
2013-03-26 12:46   ` Peter Zijlstra
2013-03-26 12:46     ` Peter Zijlstra
2013-03-26 13:53     ` Vincent Guittot
2013-03-26 13:53       ` Vincent Guittot
2013-03-26 15:29     ` Arjan van de Ven
2013-03-26 15:29       ` Arjan van de Ven
2013-03-27  8:46       ` Peter Zijlstra
2013-03-27  8:46         ` Peter Zijlstra
2013-03-27  8:54         ` Vincent Guittot
2013-03-27  8:54           ` Vincent Guittot
2013-03-27  9:00           ` Peter Zijlstra
2013-03-27  9:00             ` Peter Zijlstra
2013-03-27 11:18             ` Catalin Marinas
2013-03-27 14:13               ` Peter Zijlstra
2013-03-27 16:36                 ` Catalin Marinas
2013-03-27 17:18                   ` Nicolas Pitre
2013-03-27 17:18                     ` Nicolas Pitre
2013-03-27 17:37                     ` Catalin Marinas
2013-03-27 17:37                       ` Catalin Marinas
2013-03-27 17:20                   ` Vincent Guittot
2013-03-27 18:01                     ` Catalin Marinas
2013-03-27 15:37           ` Nicolas Pitre
2013-03-27 15:37             ` Nicolas Pitre
2013-03-22 12:25 ` [RFC PATCH v3 4/6] sched: secure access to other CPU statistics Vincent Guittot
2013-03-22 12:25   ` Vincent Guittot
2013-03-26 12:50   ` Peter Zijlstra
2013-03-26 12:50     ` Peter Zijlstra
2013-03-26 13:06     ` Vincent Guittot
2013-03-26 13:06       ` Vincent Guittot
2013-03-22 12:25 ` [RFC PATCH v3 5/6] sched: pack the idle load balance Vincent Guittot
2013-03-22 12:25   ` Vincent Guittot
2013-03-26 12:52   ` Peter Zijlstra
2013-03-26 12:52     ` Peter Zijlstra
2013-03-26 14:03     ` Vincent Guittot
2013-03-26 14:03       ` Vincent Guittot
2013-03-26 14:42       ` Peter Zijlstra
2013-03-26 14:42         ` Peter Zijlstra
2013-03-26 15:55         ` Vincent Guittot
2013-03-26 15:55           ` Vincent Guittot
2013-03-27  4:56           ` Alex Shi
2013-03-27  4:56             ` Alex Shi
2013-03-27  8:05             ` Vincent Guittot
2013-03-27  8:05               ` Vincent Guittot
2013-03-27  8:47               ` Alex Shi
2013-03-27  8:47                 ` Alex Shi
2013-03-27 10:30                 ` Vincent Guittot
2013-03-27 10:30                   ` Vincent Guittot
2013-03-27 13:32                   ` Alex Shi
2013-03-27 13:32                     ` Alex Shi
2013-03-27  8:49             ` Peter Zijlstra
2013-03-27  8:49               ` Peter Zijlstra
2013-04-05 11:08         ` Vincent Guittot
2013-04-05 11:08           ` Vincent Guittot
2013-04-22  5:45           ` Preeti U Murthy
2013-04-22  5:45             ` Preeti U Murthy
     [not found]             ` <CAKfTPtCCCifC=c+xjjnAH_HSqkR80PiQoddQKXPHuZwZawbvcA@mail.gmail.com>
2013-04-23  2:23               ` Alex Shi
2013-04-23  2:23                 ` Alex Shi
2013-04-23  4:57                 ` Preeti U Murthy
2013-04-23  4:57                   ` Preeti U Murthy
2013-04-23 15:30                 ` Arjan van de Ven
2013-04-23 15:30                   ` Arjan van de Ven
2013-04-26 10:54                   ` Peter Zijlstra
2013-04-26 10:54                     ` Peter Zijlstra
2013-04-23  4:36               ` Preeti U Murthy
2013-04-23  4:36                 ` Preeti U Murthy
2013-03-22 12:25 ` [RFC PATCH v3 6/6] ARM: sched: clear SD_SHARE_POWERDOMAIN Vincent Guittot
2013-03-22 12:25   ` Vincent Guittot
2013-03-23 11:55 ` [RFC PATCH v3 0/6] sched: packing small tasks Preeti U Murthy
2013-03-23 11:55   ` Preeti U Murthy
2013-03-25  9:58   ` Vincent Guittot
2013-03-25  9:58     ` Vincent Guittot

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